doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Annealing before re-casing, is this BS ?

Every so often I read where someone has a shotgun frame that's come back warped after being re-cased. The barrels will no longer fit. The gent starts a thread on one of the websites and asks how to correct the problem. And in reply people will pipe in and say... too bad... sorry but you goofed up by not having the frame annealed before the re-casing.

Although I'm not a metallurgist myself I know that heating steel to a red hot state (as is done in case hardening) will make it softer and relieve internal stresses. Interesting.... because that's the definition of annealing.

What I'm saying is the steel is annealed in the first part of the normal case hardening process, then it's quenched. So, is there any reason to anneal the frame in a separate step before the case hardening is done? Isn't that redundant?

I'm beginning to think the separate annealing step is nothing more than a theory/excuse/BS for a problem that isn't understood very well.

What am I missing here? Thoughts anyone? Thank you. Silvers

I sort of see what you're getting at except that to get a dead soft condition as a final result, controlled rate of cooling in a furnace would be part of the definition of annealing. How about blocking and fixturing of the frame before it's in the pack? Didn't O. G. resort to that? How much does that contribute to restraining distortion? Do the usual suspects in recasing take that precaution?

jack

Silvers,
Somewhere I'd read the same - anneal before re-case - even if you're not engraving.

I asked the guys at Classic Guns about this exact thing... and heard a couple seconds of dead air while John suffered another ding-a-ling question from a tirekicker. He politely said he didn't find annealing beforehand added any extra measure of protection against warpage. He would anneal first for $25 if I insisted, and then clearly reiterated his position.

It seems to me that if one wishes to polish the metal to perfection before hardening, it is necessary to anneal. Certain it is the case where any engraving work is anticipated. Perhaps I am in error and am more than willing to stand corrected.
Best,
John

All firearms that are to be engraved are first annealed. This certainly makes polishing much faster and easier. John always anneals firearms intrusted to me before I start work. he blocks and braces the action & side plates when present when doing this service. After engraving, he blocks and braces same piece when color casing --- after many years of using his service I haven't had a warped frame come back. FWIW, Ken

I thought you guys would have figured out by now that re-case coloring SxS's is a bad bet.

I'll have to take some pics of the two actions that just came back from John Gillette. I dont mind the odds really if the guy doing the work knows what hes doing, and John does. One of the actions sports a bit o scratchin from Mr. Ken, looks Ok to my eye.
Steve

Yeti,
I think if you really pushed John for a definitive answer he would say "anneal the frame". I was at John's shop for a few minutes today and we discussed the very same issue. He would very much prefer to anneal the frame before re-case. I also remember having the very same discussion with Oscar. Oscar would not recase a frame unless he annealed it first to relieve stress in the steel.

Recoil Rob:
I think it depends on who is doing the work.
I would not trust most, but have and will trust a man that has a proven track record.
And speaking of records, let us make the record a correct one. Case coloring is the result of case hardening by heat and quenching. OR, and the OR in large letters, a chemical process such as cyanide where hardening by heat and quenching is not done.
Best,
John

Thanks everyone who replied so far. Just to clarify, I was asking about re-casing without doing any engraving. Also I was referring to the bone charcoal/quenching process of re-casing, not the cyanide process. Silvers